The objective of this project is to advance understanding of the mechanisms that underlie normal and abnormal puberty, and to apply this knowledge to improve existing therapy for disorders of puberty. Principal areas of investigation include the developmental changes in hypothalamic regulation of gonadotropin secretion, the behavioral changes associated with normal and abnormal pubertal development, the treatment of central precocious puberty with an analog of luteinizing hormone releasing hormone, the development of luteinizing hormone releasing hormone agonists that can be administered by an intranasal route, studies of the mechanism of premature thelarche and of the gonadotropin-independent forms of precocious puberty, the recognition and treatment of secondary causes of central precocious puberty, the treatment of the McCune-Albright syndrome with an aromatase inhibitor, and the treatment of familial male isosexual precocious puberty with combined antiandrogen and aromatase inhibitor.